This invention generally relates to laser pulse shaping and more specifically to identifying molecular characteristics with a shaped laser pulse.
The almost exclusive handedness of the essential building blocks of life, illustrated by left-handed amino acids and right-handed carbohydrates, is one of the most intriguing scientific questions. Interest in the analysis of optically active compounds has grown considerably because of their importance in the biochemical and pharmaceutical industries. In a number of cases, one optically active form of a drug is effective while the other is inactive and can have undesirable side effects. The large-scale resolution of chiral compounds is presently carried out by crystallization, by chemical reaction with chiral reagents, by chromatography (particularly, simulated moving bed (SMB) techniques) or by newer technologies (for example, membranes/automated screening or counter current extractions). Drug discovery and metabolic analysis, however, involve very small quantities of optically active compounds and could benefit from much greater sensitivity. Similarly, the search for the origin of chiral purity found in living organisms requires the ability to identify extremely small quantities of chiral compounds that may be present in meteorites. Increased chiral sensitivity has already shown that right-handed amino acids are present in a number of organisms as post translational modifications.
Some studies have been conducted using polarization pulse shaping and an evolutionary learning algorithm selecting a limited number of tests from a very large quantity of shaping variable possibilities. One such experiment is discussed in T. Brixner, et al., “Quantum Control by Ultrafast Polarization Shaping,” Phys. Rev. Lett. 92, 20-8301 (2004).